In this tutorial, we will look into various methods of checking if the two lists are equal in Python. For the two lists to be equal, each element of the first list should be equal to the second list’s corresponding element. If the two lists have the same elements, but the sequence is not the same, they will not be considered equal or identical lists.
Suppose we have
listA = [4,7,2,9,1],
listA would be equal to
listB if and only if all elements of
listB are identical to
listB = [4,7,2,9,1]. We can check whether the two lists are equal in Python using the below-explained methods.
Check Equality of Lists in Python Using the Equality
A straightforward way to check the equality of the two lists in Python is by using the equality
== operator. When the equality
== is used on the list type in Python, it returns
True if the lists are equal and
False if they are not.
The below example code demonstrates how to use the equality
== operator to check if the two lists are equal in Python.
a = [4,7,3,5,8] b = [4,7,3,5,8] c = [1,7,3,5,2] print(a == b) print(a == c)
Now, let us look into the scenario where we want to get element-wise results. Suppose we want to check which corresponding elements of the second array are equal and which are not equal.
For this, we first need to convert the lists to
NumPy array using the
np.array() method and then use the equality
== operator, which will return
False for each element.
The below example code demonstrates how to check if the elements of two lists are equal or not in Python.
import numpy as np a = [4,7,3,5,8] b = [4,7,3,5,8] c = [1,7,3,5,2] print((np.array(a) == np.array(b))) print((np.array(a) == np.array(c)))
[ True True True True True] [False True True True False]
Check Equality of Arrays in Python Using the Equality
== Operator and the
In many cases, we use the
NumPy arrays for different tasks. If we use the equality
== operator to check the equality, we will get the element-wise result, as shown in the above example code.
Therefore, to check the equality of the
NumPy arrays in Python, the
numpy.all() method has to be used to check the arrays’ equality. The
np.all() method returns
True if the elements along the given axis evaluate to
True and returns
The below example code demonstrates how to check whether the two arrays are equal or not in Python.
import numpy as np a = np.array([1,6,4,8,3]) b = np.array([1,6,4,8,3]) c = np.array([1,4,8,2,3]) print((a == b).all()) print((a == c).all())